Don,
Great questions.
It was not hard. Remove OEM lamp, connect LED lamp, insert LED lamp. Just like changing any other light bulb.
On my van, and yours also, the low beam and high beam are 2 separate lamps. This is only a low beam replacement.
You do not have to remove the headlamp. You do have to remove the dust cover. 10 minutes is actually very generous. I think both lamps took less than 5 minutes.
On my van, the noticeable difference was that there seemed to be more light, and brighter light, in the immediate area in front of the van. The obvious comparison is the brightness. Everything which used to be bathed in a dull yellow, is now brightly lit. The drawback is that your OEM headlamp housing is designed to reflect a halogen lamp. Depending on the vehicle, and it's headlamp design, results will vary. A halogen lamp will always throw a farther beam, since that is what the headlamp was designed to do.
So if you're in a wide open, unlit football field or parking lot, you will see everything in front of you with clarity, but your beam is not going 100 yards down field. Your halogen won't go 100 yards either, but will go down farther than LED. But what good is a dull light which goes downfield, if that dull yellow light doesn't allow for me to actually see? For me, being able to see what was in front of me was a higher priority. Most of my driving is in The City, where there are street lights on every block. On long stretches of unlit open road, the LED is sufficient. Driving with halogen, I found myself using the high beams on cross country road trips. With LED, I haven't had to turn on the high beams. When I'm out in the woods, or up at The Lake, with LED low beam & high beam, I no longer need offroad lights. And the fact that I'm offroad, in uneven terrain, means that I'm not going 75 MPH, and I never drive faster than I can see.
Transit Connect low beams are H11 (55 W @ 12.0 V, 1350 lm ±10% @ 13.2 V) . Transit Connect high beams are H9 (65 W @ 12.0 V, 2100 lm ±10% @ 13.2 V). So while a LED replacement may not reflect as well, you are getting about 3X the lumen.
Why did I buy this off-brand, generic? It was on sale. An Amazon.com lightning deal. I figured that I could always return it if I didn't like it.
Back in the dinosaur days, when lighting upgrade was HID kits, they all came with an external power supply because that was the only way to do it. Just like lighting fixtures that had to have a ballast. You simply couldn't wire your fluorescent T8 tubes right into the building without a ballast. The actual LED and the cooling fan had different power demands, and the driver made it possible to power both via the OEM harness plug. My pickup's LED system was designed so that the OEM plug connected to the driver, which had two separate lines going out to feed the LED and cooling fan. And the advantage was that since the LED itself rarely had a failure, you could always replace just the driver/ballast. Today's technology allows for all the necessary electronics to fit neatly into the lamp unit. There is a driver, but it's small enough to fit between the LED and fan.....so no visible external driver.
So I've got 2 cars with LED lights. I'm happy with both, because I accept the plus & minus of running LED in a halogen housing. The aftermarket has begun manufacturing units which replace the entire headlamp housing with an LED unit. These are by far superior. They're usually round, and a sealed beam, with all the drivers and cooling demands built into the same unit. I see them sold for round lights. Jeeps and Harley Davidsons are the target market. If you have an old Harley, check out the Harley Davidson Day Maker. Old VW with a round light bucket could probably use them also. And it looks like they are now in the small round fog light size, so cars like Transit Connect with round fog lights can use them.